WO2004025730A1

WO2004025730A1 - Semiconductor device and memory card using same

Info

Publication number: WO2004025730A1
Application number: PCT/JP2003/010178
Authority: WO
Inventors: Mutsumi Kikuchi; Noboru Akiyama; Hiroyuki Shoji; Fumio Murabayashi; Akihiko Kanoda; Takashi Sase; Koji Tateno
Original assignee: Renesas Technology Corp.
Priority date: 2002-08-09
Filing date: 2003-08-08
Publication date: 2004-03-25
Also published as: US7268611B2; KR100592023B1; KR20050032037A; TW200415653A; TWI241591B; JPWO2004025730A1; JP4230997B2; US20050237039A1

Abstract

A semiconductor device that is small in size without marring the efficiency of the power supply and produces reduced noise in switching and a memory card are disclosed. The semiconductor device comprises step-up circuits connected into multistage for stepping up the power supply voltage to a predetermined final output voltage, a voltage control section for controlling the output voltage at the final stage or at a stage near the final stage, and an internal device to which the final output voltage is applied. The initial stage primary step-up circuit has an inductance element, a switching element, a diode, and a drive circuit. A metal coil section of the inductance element includes a metal wiring formed at the step of fabricating the semiconductor integrated circuit, and a core section includes an insulating film between wiring layers. The insulating film is formed at the same step of fabricating the semiconductor integrated circuit. The switching element and a part of the diode are disposed below the inductance element.

Description

03 010178

Semiconductor device and memory device using the same

The present invention relates to a semiconductor device that generates a voltage higher than a power supply voltage or a voltage lower than an input voltage in an internal circuit to operate an internal element, and an electronic device such as a memory card using the semiconductor device. Background art

With the spread of portable information terminals, the use of plug-in semiconductor media to carry data has been increasing, and the amount of data to be carried has been increasing not only for text documents but also for high-quality images, voice, and moving images. For this reason, there is an increasing demand for non-volatile memories indispensable for retaining these data, especially for electrically erasable programmable read only memories (EPROMS) that can be electrically erased. The EEPROM that can be erased all at once is called flash EEPROM (hereinafter referred to as flash memory), and since high-density integration is possible by performing the erase operation collectively in units of elements or blocks, large-capacity It is widely used as a low-cost nonvolatile memory.

IC cards with flash memory are widely used in mobile phone cards, such as credit cards and cash cards, and have become increasingly multifunctional, and can store OS, application programs and data. There is a demand for a large-capacity memory and low power consumption for use in mobile phones. For this reason, microcontrollers and flash memories mounted on IC cards have been miniaturized and power supply voltages have been reduced.

In addition, as microcomputers with built-in flash memory used to control consumer electronics become more sophisticated, higher speeds and lower power consumption are required, and microcontrollers and flash memories are being miniaturized and power supply voltages are being reduced.

Flash memory requires a voltage higher than the power supply voltage when writing or erasing data, and a booster circuit is provided inside the flash memory LSI. And A circuit system called a charge pump circuit is widely used for the booster circuit. In an example of a charge pump circuit, as shown in Fig. 29, basic unit circuits consisting of a capacitor 160 and a diode 170 are arranged in multiple stages in series, and a pulsed bias voltage is applied to one terminal of the capacitor. The charge is transferred to the next step every clock to raise the voltage of the capacitive load. Another type of charge pump circuit is a double voltage rectification method, in which multiple capacitors are charged in parallel and then switched to series connection to obtain a high voltage.

As another booster circuit system, a system using a DC-DC converter circuit and a system using both a DC-DC converter circuit and a charge pump circuit are disclosed in Japanese Patent Application Laid-Open No. Hei 7-21791, respectively. This is disclosed in Japanese Unexamined Patent Publication No. Hei 8—2799786. In the case of an LSI with a built-in step-down circuit that is used when a voltage lower than the input voltage is required, a dropper-type circuit is used, or when a chopper-type step-down circuit is used, the inductor used for that is an individual component. It is provided outside the chip.

Microcomputers and flash memories mounted on IC cards, or microcontrollers with built-in flash memory, are becoming finer and the power supply voltage is being reduced. Has hardly dropped. For this reason, the difference between the input voltage and the output voltage of the booster circuit tends to increase further in the future.

In the charge pump method used in the conventional booster circuit, the boosted voltage per pump stage is a voltage obtained by subtracting the diode drop voltage from the power supply voltage, so if the power supply voltage of the LSI decreases due to the progress of miniaturization, The boost voltage per pump stage becomes smaller. Accordingly, as the power supply voltage decreases, the number of stages required to boost the voltage to a desired voltage increases, and the layout area of the circuit increases. As the memory capacity increases and the capacity increases to 1 Gbit, 4 Gbit, and 16 Gbit, the increase in the area becomes even more remarkable. In the future, the voltage of processors and memories will be reduced due to the progress of miniaturization, but the writing and erasing voltages of flash memory will hardly change. Has become.

On the other hand, conventional DC-DC converter overnight or DC-DC converter With the combined use of a charge pump circuit and a charge pump circuit, a thick film process is required to form a magnetic core and lower resistance, which are not found in the normal LSI process, for forming an inductance element. In the case of thick film wiring, there is a problem in that wiring effects are increased in circuit portions other than the inductance element, for example, in a memory lead, and fine processing becomes difficult. For this reason, it was difficult to form an on-chip inductance element, and the inductance had to be formed and stuck in a separate process or externally attached. For the above reasons, conventional DC-DC converter systems have not been booster circuit systems suitable for ordinary LSI processes.

Also, the LSI with a built-in step-down circuit has a problem that the power consumption is large due to the dropper type circuit, or the mounting area is large due to the chopper type circuit with an external inductor.

An object of the present invention is to provide a semiconductor device capable of reducing the size of a power supply while using a conventional semiconductor process and reducing noise during switching, and a memory card using the same. Disclosure of the invention

According to the present invention, a booster circuit group of a plurality of stages for boosting a power supply voltage to a predetermined final output voltage, output voltage control means connected to a booster circuit near the last stage of the booster circuit group, and an output of the booster circuit group A first stage booster circuit of the booster circuit group, which boosts a power supply voltage to a primary voltage, comprises a converter circuit including an inductance element, a switching element, and a diode. The booster circuit of the first and subsequent stages that boosts the primary voltage to a predetermined final voltage is a charge pump circuit including a capacitance element and a diode, or an inductance element, a switching element, and a diode. Inductance element, switching element, diode, output voltage control means, and internal elements that constitute the booster circuit The output voltage control means formed on the substrate controls the booster circuit near the final stage so that the final output of the booster circuit group has a stable predetermined output voltage, and supplies the output to the internal element. The internal circuit generates a voltage higher than the power supply voltage. It is a semiconductor device that operates internal elements.

The present invention is a semiconductor device in which a gate of a switching element is driven at a voltage higher than an input power supply voltage.

The gate drive circuit for driving the gate of the switching element is a semiconductor device including a booster circuit, and driving the gate of the switching element at a voltage higher than the input power supply voltage.

The present invention is a semiconductor device which controls the last-stage booster circuit so that the final output of the booster circuit group has a stable predetermined output voltage.

The present invention is a semiconductor device that controls a booster circuit immediately before a final booster circuit so that a final output of the booster circuit group has a stable predetermined output voltage. The present invention is a semiconductor device in which at least one of the converter circuits has a step-up ratio or a switching duty ratio maintained at a set value during a step-up operation.

According to the present invention, at least one of the converter circuits includes means for maintaining a boost ratio or a switching duty ratio at a set value during a boost operation and arbitrarily setting the boost ratio or the switching duty ratio. Semiconductor device.

The present invention is a semiconductor device in which at least one of the converter circuits has a switching frequency of 10 MHz or more.

The present invention relates to a semiconductor device in which an inductance element is a parallel connection type inductance element in which a plurality of layers of metal wiring and an insulating film provided between the wiring layers are provided, and the plurality of layers of metal wiring are connected in parallel. is there.

The present invention relates to a semiconductor device which generates a voltage higher than a power supply voltage in an internal circuit to operate an internal element, and a memory card using the same, wherein a plurality of booster circuits for boosting the power supply voltage to a predetermined final output voltage A voltage control unit for controlling an output voltage near the final stage, and an internal element to which the final output voltage is supplied, wherein at least an inductance element, a switching element, And a converter circuit having a driving circuit for driving the switching element. The inductance element of the bar circuit is a semiconductor device including at least a metal wiring formed in the same process as a metal wiring used for a signal wiring or a power supply wiring of an internal element.

The present invention relates to a semiconductor device which generates a voltage higher than a power supply voltage in an internal circuit to operate an internal element, and a memory card using the same, wherein a plurality of booster circuits for boosting the power supply voltage to a predetermined final output voltage And a voltage control unit for controlling an output voltage near the final stage, and an internal element to which the final output voltage is supplied. The first stage primary booster circuit includes an inductance element, a switching element, A configuration is provided in which a diode and a drive circuit are provided, and a switching element and a part of the diode are arranged below the inductance element.

Further, the switching element and the diode arranged below the inductance element are arranged on the semiconductor substrate such that the drain side region of the switching element and the anode side region of the diode face each other, and both regions are arranged. At least two or more sets of electrically connected switching elements and diodes are connected in parallel.

A step-down circuit for stepping down the input voltage to a predetermined final output voltage is provided. The step-down circuit includes an inductance element, a switching element, a diode, a drive circuit, and a control circuit. The part is arranged below the inductance element.

The switching element and the diode disposed below the inductance element are disposed on the semiconductor substrate with the source region of the switching element and the cathode side region of the diode facing each other, and both regions are electrically connected. At least two pairs of switching units and diodes that are electrically connected are connected in parallel. The booster circuit includes a first metal wiring spirally formed to form an inductance element, and a second metal wiring connected to an outer peripheral end of the first metal wiring and supplying a power supply voltage. And an interlayer connection wiring connected to the inner peripheral end of the first metal wiring and routed toward the switching element and the diffusion layer of the diode formed below the inner peripheral end, and a second connection connecting the diffusion layer. 3 metal wiring. Further, the step-down circuit includes a first metal wiring wired in a spiral shape forming an inductance element, and a switching element connected to an inner peripheral end of the first metal wiring and formed below the inner peripheral end. And a third metal wiring connecting the diffusion layers, and a step-down final output voltage connected to an outer peripheral end of the first metal wiring. And a fourth metal wiring for outputting.

Further, the inductance element has a configuration including a first metal wiring and a wiring interlayer insulating film.

In addition, a plurality of the above-described semiconductor devices are provided, and the semiconductor devices are arranged so as to be overlapped with each other. The inductance element in the adjacent semiconductor device is placed in a direction directly above and below the inductance element in another semiconductor device. The configuration is such that the sunset elements are arranged so as not to overlap with each other.

In addition, a plurality of semiconductor devices are formed on a semiconductor chip, an inductance element of the semiconductor device is formed in a portion on one half side of the semiconductor chip, and an inductance element of another semiconductor device adjacent to the semiconductor device is formed on the other half of the chip. The configuration is a multi-chip type semiconductor device formed on a part of the side.

In addition, the semiconductor device that has been improved is a nonvolatile memory or a microcomputer with a built-in nonvolatile memory, and is configured to be a flash memory or a microcomputer with a built-in flash memory.

In addition, a memory card including the above-described semiconductor device and the CPU is configured. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing one embodiment of a booster circuit of a semiconductor device according to the present invention. FIG. 2 is a diagram showing one circuit configuration of the primary booster circuit of the semiconductor device according to the present invention. FIG. 3 is a diagram illustrating an operation example of the primary booster circuit of the semiconductor device according to the present invention. FIG. 4 is a circuit block diagram showing voltage control means of the semiconductor device according to the present invention. FIG. 5 is a block diagram showing the duty ratio generating circuit and the duty ratio setting means of the booster circuit of the semiconductor device according to the present invention. FIG. 6 shows a semiconductor device according to the present invention. FIG. 3 is a block diagram showing a duty ratio generation circuit and a duty ratio setting means of the booster circuit. FIG. 7 is a block diagram showing the duty ratio generating circuit and the duty ratio setting means of the booster circuit of the semiconductor device according to the present invention. FIG. 8 is an element arrangement and wiring diagram showing a first embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 9 is a diagram showing a plan view of the first embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 10 is an element layout and wiring diagram showing a second embodiment of the on-chip comparator of the semiconductor device according to the present invention. FIG. 11 is a view showing a cross section of the second embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 12 is a device layout and wiring diagram showing a third embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 13 is a plan view showing another configuration example of the inductance element in the third embodiment of the on-chip converter. FIG. 14 is an element arrangement and wiring diagram showing a fourth embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 15 is a diagram showing one plane of the on-chip inductance element of the semiconductor device according to the present invention. FIG. 16 is a view showing a cross section of the third embodiment of the on-chip comparator of the semiconductor device according to the present invention. FIG. 17 is a diagram showing the relationship between the area ratio and the power supply voltage of the booster circuit of the semiconductor device according to the present invention and the conventional booster circuit. FIG. 18 is a diagram showing the relationship between the area ratio of the booster circuit of the semiconductor device according to the present invention and the conventional booster circuit and the operating frequency. FIG. 19 is an element layout and wiring diagram showing a fifth embodiment of the on-chip comparator of the semiconductor device according to the present invention. FIG. 20 is a diagram showing a clock waveform when the inductance element is operated in parallel switching operation in the fifth embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 21 is a diagram showing another embodiment of the booster circuit of the semiconductor device according to the present invention. FIG. 22 is a diagram showing still another embodiment of the booster circuit of the semiconductor device according to the present invention. FIG. 23 is a diagram showing one embodiment of the step-down circuit of the semiconductor device according to the present invention. FIG. 24 is an element arrangement and wiring diagram showing a fifth embodiment of the on-chip converter of the semiconductor device according to the present invention. FIG. 25 is a diagram showing a configuration of a microcomputer having a built-in flash memory using the on-chip comparator of the present invention. Figure 26 shows a system port using a microcomputer with a built-in flash memory using the on-chip converter of the present invention. FIG. FIG. 27 is a diagram showing one embodiment of a multi-chip semiconductor device using the semiconductor device according to the present invention. FIG. 28 is a diagram showing one embodiment of a memory card using the semiconductor device according to the present invention. FIG. 29 is a diagram showing one embodiment of a conventional charge pump type booster circuit. FIG. 30 is a diagram for explaining a conventional gate peripheral circuit of the DC-DC comparator overnight circuit. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a diagram showing a configuration of a booster circuit of a flash memory using an on-chip converter of the present invention.

The boosting power supply circuit inside the flash memory outputs a plurality of voltages and supplies them to the memory cells. In this embodiment, a part of them will be described. The input power supply voltage 101 to the flash memory is input to the primary booster circuit 100. A secondary booster circuit 200 is connected to the output of the primary booster circuit 100, and is connected in series to an N-th booster circuit in order. That is, a plurality of booster circuits are connected in series to form a group of booster circuits. The N-th booster circuit 900 in the final stage has a voltage controller 910 controlling the output voltage 902 output from the final stage, and the memory cell 100 0 of the internal element is connected to the end of the voltage controller 910. You. The first stage primary booster circuit 100 is a step-up DC-DC converter circuit, and includes an inductance element 110, a switching element 120, a diode 130, and a gate drive circuit 140 for the switching element. It consists of an output smoothing capacitor 150. The secondary booster circuit 200 to the N-th booster circuit 900 are composed of a boost DC-DC converter circuit or a charge pump circuit.

When there is a request for writing, erasing, reading, etc. to the memory, the boosting power supply circuit inside the flash memory starts boosting operation to supply a predetermined voltage to the memory cells.

Fig. 2 shows the basic circuit diagram of the step-up DC-DC converter circuit and Fig. 3 shows the step-up operation waveform.

First, when the output signal CLK of the drive circuit 140 rises (low voltage-high voltage), the switching element 120 of the primary booster circuit is turned on, and the inductance element is turned on. A current (IL) is passed through 110 to store the energy of the magnetic field. Next, when the switching element 120 is turned off by the falling edge of CLK (high voltage-low voltage), the diode 13 is driven by the energy stored in the magnetic field so that the current of the inductance element flows continuously. The diode current (ID) flows through 0 and charges the output smoothing capacitor 150.

The diode 130 uses a MOS diode in which the drain and gate of the MOS transistor are connected. In this specification, the drain side region connected to the gate is the anode, and the source side region is the power. Called a sword. In addition, a Schottky diode other than the MOS type diode, a PN junction diode, or the like can be used as the diode 130 by considering the recovery characteristics from ON to OFF. The input power supply voltage is boosted by repeating the above switching. This is shown in FIG. 3 for the output voltage V X of the inductance element 110 and the output voltage V out of the primary booster circuit 100. The boosted output voltage Vout is input to the secondary booster circuit. At this time, if the on time of the switching element is Ton and the off time is Toff, and the magnetic flux accumulated during the period of Ton is released during the period of Toff, the output voltage Vout is (Ton + Tof f) / Tof f times. That is, the boost ratio is determined by the switching duty ratio.

In this embodiment, the circuit size of the drive circuit 140 can be reduced by setting the switching duty ratio to a fixed value and a fixed boosting ratio.

The drive circuit 140 for driving the gate of the switching element 120 includes a gate booster circuit (not shown) therein. Then, by driving the gate of the switching element with a voltage higher than the input power supply voltage 101, the gate width of the switching element can be reduced. As a result, not only can the layout area of the switching element be reduced, but also the gate capacitance and drain junction capacitance of the switching element are reduced, and the charge loss of those capacitances can be reduced. The efficiency of the entire booster circuit 100 is improved. Furthermore, since the area for laying out the switching elements can be reduced, the length of the wiring inside them can be shortened, so that the loss due to wiring resistance can be reduced. Although the charge pump circuit is used for the gate booster circuit inside the drive circuit 140, it is sufficient if the output voltage of the drive circuit is higher than the input power supply voltage 101. For this reason, the boosting ratio of the gate boosting circuit can be made lower than the overall boosting ratio of the boosting circuit 100. Further, the load capacity of the gate booster circuit is only the gate capacity of the switching element, and is smaller than the load of the booster circuit 100. From the above, the circuit scale of the gate booster circuit can be reduced as compared with the case where the entire booster circuit is realized by a charge pump circuit, and the area that can be accommodated below the inductance element 110 is reduced. Can be suppressed. In this embodiment, when the DC-DC converter circuit is used after the primary boosting circuit, the voltage is boosted at a fixed boosting ratio for each boosting circuit as necessary. Then, after reaching the N-th booster circuit in the final stage, the voltage is controlled to a predetermined voltage and supplied to the memory cells. Also, when a charge pump circuit is used after the primary booster circuit, similarly, if necessary, each booster circuit boosts the voltage at a fixed boosting ratio. Then, after reaching the N-th booster circuit in the final stage, the voltage is controlled to a predetermined voltage and supplied to the memory cells.

Also, it is possible to control the voltage to a predetermined voltage in the N-primary booster circuit immediately before the final stage, further increase the voltage by a fixed boost ratio in the final N-stage booster circuit, and then supply the boosted voltage to the memory cells. Voltage control is possible, and the circuit scale of the driving circuit 140 can be reduced. Furthermore, in order to achieve both a reduction in the circuit scale and obtaining a highly accurate voltage, the voltage may be controlled by both the N-th booster circuit and the N-first booster circuit in the final stage. According to the present invention, by using a DC-DC converter circuit as the primary booster circuit, the driving capability of the switching element can ensure the inductance current even when the input power supply voltage drops to about 1 V or less. By determining, the pressure can be increased. In other words, if the energy of the magnetic field exceeding the energy required for the subsequent load can be stored in the inductance element, the voltage can be boosted. Further, the driving circuit and the voltage control means are simplified, and the layout area of the boosting power supply circuit can be reduced.

On the other hand, in a conventional charge pump circuit, charge is stored in a capacitor, and a pulse-like bias voltage is applied to one terminal of the capacitor to transfer the charge to the next step. Each step has a diode to prevent charge backflow. Since the boost voltage for one step is the voltage obtained by subtracting the diode forward drop voltage from the power supply voltage, when the power supply voltage drops to about 1 V, the diode voltage becomes dominant, and boosting becomes almost impossible.

FIG. 4 is a block diagram showing an example of the voltage control means 9110 for controlling the magnitude of the output voltage at the final stage. This voltage control means 910 connects a plurality of MOS-type diodes 920 having their gates and drains short-circuited in series such that the sum of their threshold voltages becomes a predetermined voltage. The circuit is such that the current flowing when the output voltage of the booster circuit 900 at the stage exceeds a predetermined voltage becomes a constant current. The smoothing capacitor 15 1 is connected to the output terminal of the booster circuit 900.

When the voltage taken out of the MOS diodes 920 connected in series exceeds a predetermined voltage, a constant current flows, and the comparator 9222 generates a stop signal to prevent the voltage from rising. On the other hand, when the voltage taken out of the MOS diode 920 falls below a predetermined voltage, the comparator 922 gives a start-up signal to the transmitter 904, and raises the voltage of the N-th stage booster circuit 900. Control and increase its output voltage. In this embodiment, the voltage control means is provided in the booster circuit of the final stage. However, the voltage control means may be provided near the final stage, for example, in the preceding stage, and the final stage may have a constant boost ratio.

In this way, the constant current is converted into an appropriate constant voltage, and the constant voltage is compared with the reference voltage by the comparator 922 to obtain the oscillation input to the N-th booster circuit 900. The output voltage of the circuit 904 is turned on and off to obtain a constant predetermined voltage. Therefore, the intermediate voltage is roughly handled with a fixed boost ratio, and only the output voltage of the final stage is controlled, so that the circuit scale can be reduced.

Here, the reason why the circuit scale of the gate drive circuit 140 can be reduced by setting the switching duty ratio to a fixed value and a fixed boosting ratio will be described in detail. First, for comparison, a description will be given of a control method of a conventional DC-DC converter integrated circuit that boosts the input voltage 6101 shown in FIG. 30 to the output voltage 6102.

The gate drive circuit 140 corresponds to the gate control circuit 6140. First, the output voltage 6 102 is fed back through the filter 6 1 4 1 to generate the reference voltage. The error from the output of the path 6 1 4 2 is amplified by the error amplifier 6 1 4 3.

After that, the output of the error amplifier 6144 and the output of the triangular wave generation circuit 6144 are compared by the comparator 6145 to determine whether the switching element 120 is on or off, and the gate drive circuit is provided. 6 Send a signal to 1 4 6. The gate drive circuit 6146 holds the output voltage constant by changing the ratio of the ON period of the switching element 120. For this reason, circuit blocks such as the feedback filter 6 1 4 1, reference voltage generator 6 1 4 2, error amplifier 6 1 4 3, triangular wave generator 6 1 4 4, and comparator 6 1 4 5 are required. It becomes. On the other hand, in the case of the present invention, the DC-DC converter circuit alone does not perform feedback of the output voltage, but only operates the switching element 120 according to a preset switching duty ratio.

Therefore, the above-described feedback loop configuration is not required, and only a circuit for generating a fixed switching duty ratio and a gate drive circuit are sufficient, and the circuit scale can be reduced.

Further, since the gate drive circuit 140 has a simple configuration, high-frequency operation is possible. As a result, since the inductance value can be selected to be small, the area occupied by the inductance element 120 can be reduced.

The switching frequency and the switching duty ratio slightly vary due to manufacturing variations of the elements constituting the gate drive circuit 140, but the scale of the gate drive circuit 140 is narrowed as described above, and a simple configuration can be adopted. Boosting is possible.

In other words, even if the second stage booster circuit 200 of the next stage is a charge pump circuit, it is sufficient that the voltage exceeding the barrier of the diode forward drop voltage can be output from the first stage booster circuit 100. The accuracy of the boost ratio determined by the switching duty ratio may be coarse. Although the scale of the gate drive circuit 140 becomes large, a control circuit for stabilizing the switching duty ratio can be used.

Further, a means may be provided to enable the switching duty ratio to be set from the outside not only at the time of design but also at the time of manufacture and operation. FIGS. 5 to 7 show an example of a duty ratio generation circuit and a means for setting the duty ratio.

Figure 5 is a block diagram showing a duty ratio generation circuit using a counter and a comparator. Gram. The operation of the circuit is as follows: a rectangular wave 7002 is output from the oscillator 7001, the number of pulses is counted by the counter 7003, and the digital value set by the duty ratio setting section 7007 is used. 08 and the counter output 704 are compared by a comparator 705 to generate a switching signal 706 having a desired duty ratio.

Then, the switching signal 7006 is input to the gate drive circuit 140, and the switching element 120 is amplified so as to be driven, and then the gate is driven. When a set of a period value and a value of a switch-on period or a counter with a fixed period is used as the counter 7003, the set value 7008 may be only the value of the switch-on or off period. In this way, a desired switching duty ratio can be obtained even when the duty ratio of the oscillator 7001 is not managed.

The oscillator 7001 that generates the rectangular wave 7002 has been described as being arranged as a part of the duty ratio generation circuit. However, when a plurality of DC-DC converter booster circuits having different boost ratios are used, the oscillator is used. May be used in common, or a clock supplied from outside the LSI may be used as the rectangular wave 7002.

Note that an oscillator and a duty ratio generation circuit may be provided in all of the gate drive circuits of each booster circuit. In addition, it is possible to use a common oscillator and directly input it to the charge pump circuit type booster circuit, and to separately arrange the duty ratio generation circuit in the DC-DC converter single-circuit type booster circuit. Naturally, boosting circuits having the same duty ratio can share the duty ratio generating circuit.

Figure 6 is a block diagram showing a duty ratio generator using a triangular wave output oscillator. The threshold value 7110 which is the output of the threshold voltage generation circuit 710 is determined based on the value 708 set by the duty ratio setting section 707. The comparator 710 compares the threshold value 711 with the instantaneous value 710 of the triangular wave from the triangular wave oscillator 710 and outputs a switching signal 710 having a desired duty ratio. Generate 6.

Fig. 7 shows an example of an oscillator circuit that can change the duty ratio of the oscillator itself. The oscillator 7510 uses the two sets of CR delay time constants (75007a * 7507c and 75007b * 7507d) as the duty ratio setting section 75007. have. Assuming that the ratio is tl: t2, the duty ratio of the switching signal 706 is t1: t1 + t2. The duty ratio setting section 7507 has a resistance 7507 a adjustable, and the other capacitances 7507 c and 7507 d are fixed at the same value. Yes, and the resistance 7507b is fixed.

The setting value of the duty ratio setting section 7007 described in Fig. 6 and Fig. 7 depends on the presence or absence of wiring connection by fuse, wiring mask option, contact placement mask option, or terminal connection option at mounting. There is a method of retaining 708, and a method of retaining the set value using a rewritable storage element such as a nonvolatile memory or a register. When a register is used, it is necessary to determine the value when the power is turned on, and a configuration in which the set value is read from a nonvolatile memory or the like can be considered.

It is possible to directly change the resistance value or capacitance value by changing the wiring connection such as the fuse wiring option, but it is also possible to indirectly set the value. Conversely, if means for holding the value of a non-volatile memory or register is used for the duty ratio setting, a method of switching the switch element so as to change the resistance value or the capacitance value based on the value is also considered. Can be

The comparator of the DC-DC converter with the conventional configuration shown in Fig. 30 needs to configure a differential amplifier to compare voltages. However, the comparator of the duty ratio setting method using the counter of the embodiment of the present invention shown in FIG. 5 can be configured by a logic circuit, and the circuit area is smaller than that of the differential amplifier. Although a differential amplifier is required in Fig. 6, the phase design is simplified because the duty ratio is set directly without forming a feedback control loop.

In the embodiments shown in FIGS. 5 to 7, the boost ratio is indirectly determined by the switching duty ratio. However, a block (not shown) for converting the boost ratio into a duty ratio is provided to set the boost ratio. It may be a value.

By making the boost ratio setting changeable in this way, the switching duty ratio operates when the input voltage to the memory LSI is 3 V during high-speed operation, but drops to IV during low-power operation. By changing the mode inside the LSI according to the mode, it is possible to respond to changes in input voltage without changing the circuit configuration. High-speed operation product It is also possible to manufacture a seed and a low-speed but low-power-consumption model as the same chip, and change the internal register at the time of shipment to separate the models.

According to the present embodiment, the first-stage booster circuit is a DC-DC converter circuit, so that even if the input power supply voltage drops to about IV or less, the switching element 1 20 Can be boosted by determining the driving capability of the device. That is, if the energy of the magnetic field exceeding the energy required for the subsequent load can be stored in the inductance element 110, the voltage can be boosted.

Also, the drive circuit and the voltage control means are simplified, and the layout area of the boost power supply circuit can be reduced. On the other hand, in the charge pump circuit, charge is stored in a capacitor, and a pulse-like bias voltage is applied to one terminal of the capacitor to transfer the charge to the next step. A diode is required for each step to prevent the backflow of charges.

Since the boost voltage for one step is a voltage obtained by subtracting the forward voltage drop of the diode from the power supply voltage, when the power supply voltage drops to about 1 V, the voltage of the diode becomes dominant, and boosting hardly occurs. Will be possible.

FIG. 8 shows a first embodiment of the on-chip converter of the present invention. FIG. 9 is a diagram showing an arrangement of an inductance element 110 constituting an on-chip converter, a switching element 120 and a diode 130 which are peripheral elements thereof, and a connection relationship with an inductance element. The area where the switching element 120 is formed is indicated by M, and the area where the diode 130 is formed is indicated by D. FIG. 9 shows a plan configuration of the first embodiment of the on-chip converter of the present invention. As shown in Fig. 9, the converter is formed in a partial area of the semiconductor chip. After the input power supply voltage 101 is boosted by the circuit shown in Fig. 1 (only the converter section is shown in Fig. 9), the elements inside the chip ( For example, a flash memory device (not shown) is driven.

The metal wiring portion 111, which is the first metal wiring of the inductance element 110, is formed of the metal wiring used for the signal wiring or the power supply wiring of the flash memory element inside the semiconductor chip in FIG. 9 in the flash memory element. The second-layer metal wiring used for signal wiring is formed in a spiral shape. The core of the inductance element 110 is formed of a wiring interlayer insulating film and a protective insulating film of the metal wiring. In the past, when an inductance element was built into a chip, the series resistance was reduced by adding a special process of thick-film wiring with a number of thicknesses / xm or laminating ones processed by another process. In the present invention, as described above, for example, the inductance element 110 is formed on-chip without modifying the wiring process of the flash memory.

The details of the structure will be described later in the description of the parallel connection type inductance with reference to schematic cross-sectional views; FIG. 16 (a) to FIG. 16 (c).

The second metal wiring for supplying the input power supply voltage 101 is connected to the outer peripheral end of the metal wiring part 111 of the inductance element 110, and is lowered from the inner peripheral end of the metal wiring part 111 to the board side. The interlayer connection wiring 18 1 is connected to a first-layer metal wiring m 1, which is a third metal wiring connecting the switching element 120 and the diffusion layer (not shown) of the diode 130. The metal wiring m1 is composed of metal wirings m1a and m1b, and m1a extends in one direction almost as much as one side of the inductance element. The region D where the diode 130 is formed is divided, and m 1b extends in a direction orthogonal to mla from a plurality of locations of m 1a, and the switching element 120 and the diffusion layer of the diode 130 (not shown) ) Is connected. For the sake of simplicity, FIGS. 8 and 9 show only the metal wiring between the switching element 120 and the diode 130 and the inductance element 110, and other wiring is omitted (unless otherwise described. The same applies to the following figures).

Further, in FIG. 8, the shape of the metal wiring portion 111 of the inductance element 110 is rectangular for simplicity, but may be another polygon such as an octagon or a hexagon. The same applies to the following embodiments.

As in the present embodiment, the switching element 120 and the diode 130 are provided directly below the inductance element 110, and the interlayer connection wiring 1 which is lowered from the inner peripheral end of the metal wiring section 111 toward the semiconductor substrate side. 8 1 is connected to the first-layer metal wiring m 1 that connects the switching element 12 0 and the diffusion layer of the diode 13 0, so that the wiring resistance and parasitic inductance between the elements can be reduced. The size of the on-chip converter can be reduced without reducing the efficiency, and the noise during switching can be reduced. You.

FIG. 10 shows a second embodiment of the on-chip converter of the present invention. FIG. 4 is a diagram showing an arrangement of an inductance element 110 constituting an on-chip converter, its peripheral elements, a switching element 120 and a diode 130, and a connection relation with an inductance element. M and the formation region of the diode 130 are indicated by D.

FIG. 11 is a diagram showing a schematic cross section of a second embodiment of the on-chip converter of the present invention. In FIG. 11, 1200 is a diffusion layer in which a MOS transistor (switching element 120) and a MOS diode (diode 130) are formed, 120D and 120S are diffusion layers forming a drain region and a source region of the switching element, respectively. And 13 OK are diffusion layers forming the anode region and the power source region of the diode, respectively.

In the formation region M of the switching element 120, two transistors Ml and M2 are provided sharing the diffusion layer 120S forming the source region, and are connected to the diffusion layer 120S via the contact wiring. The layer (metal) wiring is the GND wiring fixed to the ground potential. In the formation region D of the diode 130, two MOS diodes D1 and D2 are provided in common with the diffusion layer 130K forming the power source region, and are connected to the diffusion layer 130K via contact wiring. The first layer (metal) wiring is the Vout wiring that is the output potential of the converter circuit. Of the gate wiring, the wiring indicated by G is the gate of the switching element 120, and the wiring connected to the diffusion layer 120D (13 OA) via the contact wiring and the first-layer (metal) wiring is a MOS diode. 130 gates.

The switching element 120 and the diode 130 are each divided into a plurality, and the drain region of the switching element 120 and the anode region of the diode 130 are arranged to face each other, and both regions are formed in the same diffusion layer 120D (130A). M1 and D2 or M2 and D1 are referred to as a combination unit, and the switching element 120 and the diode 130 are configured by connecting a plurality of combination units in parallel. By adopting such a configuration, the wiring distance between the switching element 120 and the diode 130 is shorter than that of the first embodiment shown in FIG. 8, and the wiring resistance and the parasitic inductance are reduced. In addition, the size of the inductance element can be reduced, and the switching noise can be reduced.

As described above, the switching element 120 and the diode 130 are provided directly below the switching element 120, and the interlayer connection wiring 1801, which is lowered from the outer peripheral end of the metal wiring part 111 to the substrate side, By connecting to the first layer metal wiring ml that connects the switching element 120 and the diffusion layer of the diode 130, the wiring resistance between the elements and the parasitic inductance can be reduced, so that the power supply efficiency is reduced. Without downsizing, the size of the on-chip converter can be reduced, and noise during switching can be reduced.

FIG. 12 shows a third embodiment of the on-chip converter of the present invention. In this embodiment, a plurality of metal wiring portions of the inductance element 110 in FIG. 8 are arranged in parallel. As described in the previous embodiment (FIG. 8), the metal wiring portions 111 and 112 are formed of the metal wiring used for the signal wiring or the power supply wiring of the flash memory element inside the semiconductor chip. In flash memory devices, the second and third layers of metal wiring used for signal wiring and power wiring, respectively, are formed as they are.

The metal wiring sections 11 1 and 1 2 of the spiral-shaped inductance element with the same planar shape in a plurality of different wiring layers must have the same direction of magnetic flux when current is applied to them, so that the magnetic flux passes through each other. It is important to form them on top of each other and connect them in parallel. When the inductance elements of a single wiring layer are connected in parallel in such an arrangement that the magnetic flux does not interfere with each other, the resistance becomes 1 / k (k is the number of inductance elements connected in parallel). Is also reduced by a factor of k. By stacking the magnetic flux so that they penetrate each other in the same direction, the inductance value can be made almost the same as the original one-layer inductance element while reducing the resistance by a factor of k. This makes it possible to build a low-resistance inductance element on-chip without modifying the normal LSI wiring process for flash memory and the like (not shown, but each layer is formed with a through hole, etc.). Potential portion may be connected).

The metal wiring sections 1 1 1 and 1 1 2 forming the inductance element connected in parallel are If they are spiral shapes, they do not necessarily have to have the same shape and the same size. For example, the shape of 111 may be a square and the shape of 112 may be an octagon, as long as the magnetic flux penetrates each other. Also, as shown in FIG. 13, when 111 is projected onto 112, if the spiral center points 111a and 112a of 111 and 112 do not deviate from the other spiral metal wiring parts, the center point Do not necessarily have to match. Further, by using an inductance element connected in parallel with multilayer wiring, it is possible to suppress an increase in resistance due to a skin effect when the operation of the switching element 120 is performed at a high frequency. In order to make the inductance element smaller, high-frequency switching is required. However, when the frequency exceeds 20 MHz, a skin effect appears, and current concentrates only on the surface of the conductor. In this case, even if a low-resistance inductance element is to be constituted by wiring having a thickness of several m, the resistance increases because current cannot flow through the entire conductor cross section. However, in an inductance element composed of multiple wiring layers connected in parallel, even if the total cross-sectional area is the same, the conductor surface area is larger than that of the thick-film wiring, so that the rise in resistance due to the skin effect can be suppressed to a small extent. There is an advantage. FIG. 14 shows a fourth embodiment of the present invention. In the present embodiment, the metal wiring portions 111 and 112 in FIG. 12 are formed by the third-layer wiring and the fourth-layer wiring, respectively, and the diffusion layer of the switching element 120 and the diode 130 is formed by the first-layer wiring and the second-layer wiring. This is an embodiment in which a metal wiring ml for connecting (not shown) is formed. When the sheet resistance of the first-layer metal wiring is large, it is effective to reduce the wiring resistance between the metal wiring part and the switching element or diode.

FIG. 15 is a plan view of the metal wiring portion 111 of the inductance element shown in FIG. 12, and FIGS. 16 (a) to 16 (c) are cross-sectional views taken along lines AA ', BB', and CC.

In FIG. 15, reference numerals 180a to 189a indicate connection points between the interlayer connection wires 180 to 189 and the metal wiring portion 111, respectively.

In each of FIGS. 16A to 16C, the inductance element 110 is connected in parallel with the second and third metal wiring layers and the wiring interlayer insulating film and the protective insulating film provided between the metal wiring layers. Type inductance element. In other words, metal wiring and wiring Inductance sinter having a plurality of layers of interlayer insulating films connected in parallel. The metal wiring forming the inductance element is a spiral wiring composed of a plurality of layers of metal wiring as shown in FIGS. 12 and 15, and the outer peripheral end of the spiral wiring has an input power supply voltage. 101 is supplied. In each spiral wiring, the outer peripheral end is connected to each other by an interlayer connecting wiring 180, and the interlayer connecting wiring 181, which is lowered from the inner peripheral end to the board side, intersects the first-layer metal wiring m1a; 16 (a) ₀ Then, the metal wiring mla extends in the BB 'direction almost as much as one side of the inductance element; Fig. 16 (b). A region M where the switching element 120 is formed (120a in FIG. 16) and a region D where the diode 130 is formed D (130a in FIG. 16) are divided by the metal wiring mla, and m A metal wiring m 1 b extends in a C-C ′ direction from a plurality of locations of 1 a; FIG. 12, connected to a diffusion layer (not shown) of a switching element 120 and a diode 130; (c

FIG. 17 is an explanatory diagram showing the relationship between the area ratio and the power supply voltage when the primary boosting voltage is increased to 7 V for the boosting circuit of the present invention and the conventional boosting circuit. In a conventional booster circuit using a charge pump circuit, the circuit area increases as the power supply voltage decreases, and the area increases rapidly when the power supply voltage is 2 V or less, whereas the circuit area increases when the booster circuit of the present invention is used. There is almost no increase, and the area is smaller than that of the conventional circuit method at about 2.5 V. The reason that the area of the conventional booster circuit rapidly increases when the power supply voltage is 2 V or less is that the boost voltage per pump stage in the charge pump circuit is lower than the power supply voltage by the M〇S type diode drop voltage (the effect of the substrate bias). (Approximately IV or more), and the number of charge pump circuits required for boosting increases. On the other hand, according to the present invention, when the output voltage of the primary booster circuit 102 is about 7 V, the voltage can be boosted in one stage, and therefore, the influence of the MOS type diode drop voltage is not so large. Absent. FIG. 18 is an explanatory diagram showing the relationship between the area ratio and the operating frequency when the primary boosting voltage is increased to 7 V for the boosting circuit of the present invention and the conventional boosting circuit. When the operating frequency of the booster circuit is about 10 MHz or higher, the size of the booster circuit of the present invention is smaller than that of the conventional booster circuit. This is because the size of the capacitor, which largely determines the size of the charge pump circuit, is inversely proportional to the switching frequency of the pump. This is because the size of the inductance element, which determines the size of the DC converter and the circuit, is inversely proportional to the square of the switching frequency.

FIG. 19 shows a fifth embodiment of the present invention. The arrangement of the switching element 120 and the diode 130 is not shown for simplicity, but four converters having the same configuration and reduced size as the converter shown in FIG. 12 are arranged. The maximum current consumption and average current of the DC-DC converter circuit shown in Fig. 2 are determined by the inductance current IL, and the maximum current increases and is about twice the average current. Therefore, the load on the input power supply of the flash memory may be increased.

To solve this, as shown in Fig. 19, as shown in Fig. 12, a plurality of pairs of the inductance elements 110 are arranged so that the total inductance value is the same (110 a, 110 b, 110 c, 110 d) and four switching elements are also provided, and they are operated in parallel with a difference in the switching phase as shown in Fig. 20. To reduce the total peak.

In the case where the area of one inductance element is 1 / k, and k pieces are operated in parallel, if the switching frequency is multiplied by (k ³ ), the average current is the same as before k division. The maximum current of each phase is 1 / k, and the total is less than 1. Therefore, it is possible to reduce the total maximum current. Furthermore, when the switching phases are operated in parallel with a difference of 1 / k of the period, the total inductance current can be minimized, and the maximum current can be reduced.

The relationship between the step-up ratio and the switching duty ratio has been described above. By operating with, the ripple of the total current of each phase is eliminated, and the average current and the total maximum current can be made almost the same. In addition, when divided, the degree of freedom in the arrangement of the inductance element increases. For example, it can be arranged not only in a square area but also in a rectangular area.

FIG. 21 shows a case where N = 2 in the embodiment of FIG. 1, and a limiter 103 is arranged at the output of the first-stage booster circuit 100. In this case, the boosting can be advanced to an intermediate stage in advance in preparation for the start of the operation of the second booster circuit 200, so that the entire boosting operation is performed. Memory access speed. Note that the limiters 103 and 203 can use the same circuit system as that described as an example of the voltage control means 910 of FIG.

FIG. 22 is a diagram showing a configuration of a booster circuit inside a flash memory according to another embodiment of the present invention. The boosting power supply circuit inside the flash memory outputs a plurality of voltages and supplies them to the memory cells. In the present embodiment, a part of them will be described. The input power supply voltage 5101 to the flash memory is input to the first stage booster circuit 5100.

Then, the output of the first-stage booster circuit 5100 is connected to the second-stage booster circuit 5200, and thereafter the N-stage booster circuits are sequentially connected in series. The N-stage booster circuit 5900 has voltage control means 5910 for controlling the output voltage 5902, and the memory cell 1000 is connected to the voltage control means 5910. The first-stage boost circuit 510 is a charge pump circuit, and the second-stage boost circuit 520 uses a DC-DC converter circuit.

Although not shown here, the third to N-th boost circuits 900 are composed of boost DC-DC converter circuits or charge pump circuits. When the input power supply voltage V in is boosted by a times using a charge pump circuit in the first stage booster circuit, the input maximum current I in 2 of the second stage booster circuit is the DC resistance of the inductance element and the switching element by R. When dc, I in 2 = a * V in / R dc.

If the inductance value is L, the stored energy is l / 2L * I in2 * I in2, so the stored energy is less than a of 2 if the input power supply voltage is not directly input to the DC-DC comparator circuit. It becomes a multiplication. For these reasons, an efficient booster circuit can be configured by using the first-stage booster circuit as a charge pump circuit and the second-stage booster circuit as a DC-DC converter circuit.

However, if the boost ratio of the first-stage boost circuit is higher than the boost ratio of the second-stage boost circuit, the area of the charge pump circuit may increase because the scale of the charge pump circuit increases. Therefore, it is necessary to make the boosting ratio of the second-stage boosting circuit larger than that of the first-stage boosting circuit.

FIG. 23 shows an embodiment of a step-down circuit using the on-chip converter of the present invention. Ko The amplifier circuit includes an inductance element 110, a switching element 121, a diode 131, a gate drive circuit 141 for a switching element, a control circuit 142 for controlling an output voltage, and an output smoothing capacitor 151. The high voltage 1010 input to the circuit is output as a predetermined low voltage 1020. The layout, wiring, plane configuration, and cross-sectional configuration of the inductance element 110 and the peripheral elements, the switching element 121 and the diode 131, which form the on-chip comparator are shown in Figs. FIGS. 12, 14 and 9, FIG. 11, and FIGS. 16 (a) to 16 (c) are substantially the same, but as shown in FIG. The fourth metal wiring that outputs the reduced voltage is connected instead of the wiring that supplies 101. Also, as in the configuration shown in FIG. 11, when a combination of the switching element 121 and the diode 131 is connected in a plurality of combinations, the combination unit is connected to the source region of the switching element and the diode cathode. The regions on the semiconductor substrate side may be arranged on a semiconductor substrate so as to face each other, and both regions may be electrically connected. The step-down circuit according to the present embodiment may include a plurality of stages, similarly to the step-up circuits 100, 200, and 900 shown in FIG.

In other words, a voltage control that controls the final output voltage, which is stepped down from the input voltage by a primary step-down circuit or a multi-step step-down circuit group using a plurality of steps, and output from the step-down circuit at the final stage. The structure of the semiconductor device including the portion can be adopted. FIG. 25 shows the configuration of a microcomputer with a built-in flash memory using the on-chip DC-DC converter of the present invention. The microcomputer 300 with a built-in flash memory includes a CPU 310, a flash memory 320, a RAM 330, an I / O unit 340, and the like. The I / O unit 340 includes serial I / O, programmable input / output ports, A / D conversion, D / A conversion, and the like. In the flash memory 320, for example, the booster circuit shown in FIG. 1 and the on-chip converter shown in FIG. 4 are used. FIG. 26 shows a configuration of a system board 3000 using a microcomputer 300 with a built-in flash memory using the on-chip comparator of the present invention. The system board 3000 includes a microcomputer 300 with built-in flash memory, The LSI and individual parts 3100 for the application system to be controlled are mounted.The system port 3100 is connected to the personal computer 3200 via a serial I / F, etc. The application program is transferred and written from the personal computer 320 to the built-in flash memory 320 of the flash memory built-in microcomputer 300. The microcomputer 300 with built-in flash memory described in this embodiment can be applied to a wide range of applications as an in-vehicle microcomputer for engine control and body control, and a system control microcomputer for plasma display panels (PDP) and DVD-related devices. . FIG. 27 shows an internal block diagram of two types of semiconductor devices 10 and 20 used when a plurality of semiconductor devices of the present invention are stacked and mounted. FIG. 28 shows semiconductor devices 10 and 20. 1 shows a schematic cross-sectional configuration diagram of a multi-chip type semiconductor device mounted on a card in an overlapping manner. In FIG. 27, reference numeral 10 denotes a first semiconductor device, 20 denotes a second semiconductor device, 11 and 21 denote memory cell regions, 12 and 22 denote peripheral circuit regions, and 1 11 0 and 11 1 Reference numeral 20 denotes a booster circuit region including the primary booster circuit 100 described in the present invention. Here, the semiconductor device 20 has a configuration in which the element layout of the semiconductor device 10 is mirror-inverted. For this reason, the inductance element 110 inside the booster circuit region 111 of the semiconductor device 110 is located in the left half region of the chip, and the booster circuit region 1 120 inside the semiconductor device 20. The inductance element 110 is provided in the right half area of the chip. In FIG. 28, reference numeral 40 denotes a memory card, reference numeral 30 denotes a CPU, and reference numeral 31 denotes a bonding wire that connects the CPU to electrode pads of the first semiconductor element 10 and the second semiconductor element 20. Then, the semiconductor devices 10 and 20 are overlapped so that the aa ′ cross section and the bb ′ cross section become the cross section of FIG. 28, respectively. For example, in FIG. 28, the peripheral circuit region 12 is on the back side of the booster circuit region 110 of the semiconductor device 10.

The configuration of a memory card to which a semiconductor device to which the booster circuit of the present invention is applied is described below.

The present invention provides a booster circuit group having a plurality of stages for boosting a power supply voltage to a predetermined final output voltage, a voltage controller connected to a booster circuit near the final stage, and controlling a final output voltage; The booster circuit at the first stage includes an inductance element, a switching element, a diode, and a switching element. A driving circuit for driving the switching element;

A part of the arm includes a semiconductor device arranged below the inductance element and a controlling CPU. The semiconductor device has a plurality of semiconductor devices, each of which is connected to the CPU by a bonding wire. Semiconductor devices are arranged in an overlapping manner, and the inductance elements in adjacent semiconductor devices do not overlap with each other directly above and below the inductance elements. It is a configuration arranged like this.

When a plurality of semiconductor devices are mounted in such a manner as described above, the operation may become unstable due to interference between magnetic fluxes generated from the inductance between adjacent semiconductor devices. Therefore, in such a case, the first and second semiconductor devices as shown in FIG. 27 are superimposed on each other as shown in FIG. 28, so that the inductance elements do not overlap each other up and down. There is no mutual interference between them.

In the above-described embodiments, a flash memory has been described as an example of a semiconductor device to which the present invention is applied. However, any device that generates a voltage higher than a power supply voltage in an internal circuit and drives an internal element may be used. Therefore, the present invention can be applied. The present invention can be applied to semiconductor devices other than nonvolatile memories and other memories, for example, semiconductor devices such as a microprocessor Z controller, and has an effect that it can be driven by a single dry cell voltage.

In FIG. 28, memories such as SRAM and DRAM may be superimposed together with the flash memory.

Furthermore, according to the present invention, since the power supply voltage can be reduced to about 1 V and the mounting area is reduced, the semiconductor device of the present invention or the multi-chip semiconductor device is applied to a portable electronic device such as a portable telephone or a PDA. If this is the case, it will be possible to reduce the power consumption and size of the equipment, and to reduce the mounting cost.

The reference numerals used in the above description indicate the following parts.

1 0 ... 1st semiconductor device, 1 1, 2 1 ... memory cell area, 1 2, 2 2 ... peripheral circuit area, 2 0 ... 2nd semiconductor device, 3 0 to CPU, 4 0 ... memory Card, 10.0 ... primary booster circuit, 101 ... input power supply voltage, 102 ... primary booster circuit output voltage, 103, 203 ... limiter, 104, 204 ... transmitter, 110 ... inductance element, 120, 121 ... switching element, 130 , 131, 170… Diode, 140, 141… Switching element gate drive circuit, 142… Control circuit, 150, 151… Output smoothing capacitor, 160… Capacitor, 200—Secondary booster circuit, 900-Nth booster circuit, 902: output voltage, 910: voltage controller, 100 (^-memory cell, 1110, 1120: booster circuit area. Industrial applicability

According to the present invention, it is possible to provide a semiconductor device which can be reduced in size without lowering the efficiency of a power supply and can reduce noise at the time of switching, and a memory device using the same.

Claims

The scope of the claims

1. A plurality of stages of booster circuits for boosting a power supply voltage to a predetermined final output voltage, output voltage control means connected to a booster circuit near the last stage of the booster circuit group, and an output of the booster circuit group And a first-stage booster circuit for boosting a power supply voltage to a primary voltage in the booster circuit group, comprising: a converter including an inductance element, a switching element, and a diode. The booster circuit of the first and subsequent stages configured to boost the primary voltage to a predetermined final voltage includes a charge pump circuit including a capacitance element and a diode, or an inductance element, a switching element, and a diode. An inductance element, a switching element, and a diode that constitute the booster circuit, the output voltage control means, Serial internal element is formed on a semiconductor substrate,

The semiconductor device, wherein the output voltage control means controls a booster circuit in the vicinity of the last stage, and supplies its output to the internal element.

2. A plurality of stages of booster circuits for boosting the power supply voltage to a predetermined final output voltage, output voltage control means connected to a booster circuit near the last stage of the booster circuit group, and an output of the booster circuit group And a first-stage booster circuit for boosting a power supply voltage to a primary voltage in the booster circuit group is configured by a charge pump circuit including a capacitance element and a diode. The boosting stage of any of the boosting circuits of the first and subsequent stages for boosting the primary voltage to a predetermined final voltage is configured by a comparator circuit including an inductance element, a switching element, and a diode, An inductance element, a switching element, and a diode that constitute a circuit; the output voltage control means, the internal element is formed on a semiconductor substrate;

3. The semiconductor device according to claim 2, wherein a boosting ratio of the first-stage boosting circuit is smaller than a boosting ratio of the converter circuits in the first and subsequent stages.

4. The semiconductor device according to claim 1, wherein the power supply voltage is 2.5 V or less.

5. The semiconductor device according to claim 1, wherein at least one of the converter circuits in the comparator circuit has a boost ratio maintained at a set value during a boost operation.

6. The semiconductor device according to claim 1, wherein in at least one of the converter circuits, the boost ratio is maintained at a set value during the boost operation, and the boost ratio is arbitrarily set. Semiconductor device having means.

7. The semiconductor device according to claim 1, wherein at least one of the converter circuits in the converter circuit maintains a switching duty ratio during a boosting operation at a set value.

8. The semiconductor device according to claim 1, wherein at least one of the converter circuits in the converter circuit has a switching frequency of 10 MHz or more.

9. The semiconductor device according to claim 1, wherein the inductance element includes a plurality of layers of metal wiring and an insulating film provided between the wiring layers, and the plurality of layers of metal wiring are connected in parallel. A semiconductor device that is an inductance element.

10. The semiconductor device according to claim 9, wherein the metal wiring forming the inductance element is a spiral wiring, an outer peripheral end of the spiral wiring is connected to a wiring for supplying the power supply voltage, and A semiconductor device having an end connected to a diffusion layer of the switching element formed in an element region below the inductance element via a metal wiring.

11. The semiconductor device according to claim 1, wherein the internal element operated by applying a voltage higher than a power supply voltage is a nonvolatile memory.

12. A memory card using the semiconductor device of the semiconductor device according to claim 1.

1 3. A plurality of booster circuits for boosting the power supply voltage to a predetermined final output voltage; and a voltage controller connected to the booster circuits in the plurality of booster circuits and controlling the output voltage near the final stage. When,

An internal element to which a final output voltage from the plurality of booster circuit groups is supplied, wherein at least an inductance element and a switch are provided in the plurality of booster circuit groups. A driving circuit for driving the switching element, a diode, and a driving circuit for driving the switching element.

A semiconductor device, wherein the inductance element of the converter circuit includes at least a metal wiring formed in the same step as a metal wiring used for a signal wiring or a power supply wiring of the internal element.

14. The semiconductor device according to claim 13, wherein the inductance element is a parallel connection type inductance element in which a plurality of layers of metal wirings are connected in parallel.

15. A memory card using the semiconductor device according to claim 13.

16. The semiconductor device according to claim 14, wherein the semiconductor device is a flash memory or a microcomputer with a built-in flash memory.

17. The semiconductor device according to claim 14, wherein the metal wirings of the plurality of layers forming the inductance element are formed in an area of each metal wiring forming an inductance element when they are projected and overlapped. Semiconductor devices, wherein the center points of the semiconductor devices are located within regions of other metal wirings.

1 8. Multistage booster circuit group that boosts the power supply voltage to a predetermined final output voltage, and voltage control that is connected to the booster circuits in the multistage booster circuit group and controls the output voltage near the final stage And an internal element to which a final output voltage from the plurality of stages of booster circuits is supplied, wherein at least an inductance element, a switching device, a diode, and the switching device are provided in the plurality of stages of booster circuits. And a driving circuit for driving the element. The inductance element of the converter circuit includes a metal wiring formed in the same process as a metal wiring used for a signal wiring or a power supply wiring of the internal element. A plurality of semiconductor devices including at least

The plurality of semiconductor devices are arranged so as to overlap each other, and the inductance element in the adjacent semiconductor device has an inductance element in another semiconductor device directly above and below the inductance element. A multichip semiconductor device characterized by being arranged so as not to overlap with each other.

19. The multi-chip semiconductor device according to claim 18, wherein The plurality of semiconductor devices are formed on a semiconductor chip,

The inductance element of the semiconductor device is formed on a portion of one half of a semiconductor chip, and the inductance element of another semiconductor device adjacent to the semiconductor device is formed on a portion of the other half of the chip. A multi-chip type semiconductor device characterized by being formed.

20. The multichip semiconductor device according to claim 18, wherein

The multi-chip type semiconductor device, wherein the inductance element is a parallel connection type inductance element in which a plurality of layers of metal wirings are connected in parallel.

21. The multi-chip semiconductor device according to claim 18,

A multi-chip semiconductor device, wherein the semiconductor device is a flash memory or a microcomputer with a built-in flash memory.

22. The multi-chip semiconductor device according to claim 18,

When the metal wirings of the plurality of layers forming the inductance element are projected and superimposed on each other, the center point of each area of each metal wiring forming the inductance element is within the area of another metal wiring. A multi-chip type semiconductor device, comprising:

2 3. A plurality of booster circuits for boosting the power supply voltage to a predetermined final output voltage, and a voltage controller connected to the booster circuits in the plurality of booster circuits and controlling the output voltage near the final stage When,

An internal element to which a final output voltage from the plurality of booster circuit groups is supplied; a first booster circuit in the plurality of booster circuit groups includes an inductance element, a switching element, and a diode And a drive circuit that drives the switching element.

A semiconductor device, wherein the switching element and a part of the diode of the converter circuit are arranged below the inductance element.

2 4. A step-down circuit that steps down the input voltage to a predetermined final output voltage,

The step-down circuit has a converter circuit including an inductance element, a switching element, a diode, a drive circuit for driving the switching element, and a control circuit for controlling an output voltage.

A part of the switching element and the diode of the converter circuit is A semiconductor device disposed below the inductance element.

25. The semiconductor device according to claim 23,

A first metal wiring wired in a spiral to form the inductance element;

A second metal wiring connected to an outer peripheral end of the first metal wiring and supplying the power supply voltage;

An interlayer connection wiring connected to an inner peripheral end of the first metal wiring, and wired toward the switching element and a diffusion layer of the diode formed below the inner peripheral end;

And a third metal wiring connecting the switching element and a diffusion layer of the diode.

26. The semiconductor device according to claim 24,

A first metal wiring wired in a spiral shape forming the inductance element; a switching element connected to an inner peripheral end of the first metal wiring, and formed below the inner peripheral end; and An interlayer connection wiring routed toward the diffusion layer of the diode, a third metal wiring connecting the switching element and the diffusion layer of the diode, and a step-down connected to the outer peripheral end of the first metal wiring; And a fourth metal wiring for outputting the final output voltage.

27. The semiconductor device according to claim 23,

The switching element and the diode are a combination of a switching element and a diode in which a drain side region of the switching element and an anode side region of the diode are arranged on a semiconductor substrate so as to face each other, and both regions are electrically connected. A semiconductor device having a configuration in which at least two sets of matching units are connected in parallel.

28. The semiconductor device according to claim 24,

The switching element and the diode are arranged on a semiconductor substrate such that a source-side region of the switching element and a cathode-side region of the diode face each other, and a switching element in which both regions are electrically connected. And Diode Union A semiconductor device having a configuration in which at least two sets of units are connected in parallel.

29. The semiconductor device according to claim 23,

A semiconductor device, wherein a plurality of layers each including the first metal wiring and a wiring interlayer insulating film are connected in parallel in the inductance element.

30. The semiconductor device according to claim 23,

The semiconductor device is a nonvolatile memory or a microcomputer with a built-in nonvolatile memory.

31. The semiconductor device according to claim 30,

The semiconductor device, wherein the nonvolatile memory or the microcomputer with a built-in nonvolatile memory is a flash memory or a microcomputer with a built-in flash memory.

3 2. A multi-stage booster circuit group that boosts the power supply voltage to a predetermined final output voltage, and a voltage control that is connected to the booster circuits in the multi-stage booster circuit group and controls the output voltage near the final stage And an internal element to which a final output voltage from the plurality of booster circuit groups is supplied. The first booster circuit in the plurality of booster circuit groups includes an inductance element and a switching element. And a driving circuit for driving the switching element. The switching element and a part of the diode of the converter circuit include a part of the inductance element. It has a plurality of semiconductor devices arranged below,

The plurality of semiconductor devices are arranged so as to be overlapped with each other, and the inductance element in the adjacent semiconductor device is such that inductance elements in other semiconductor devices overlap with each other in a direction directly above and below the inductance element. A multi-chip semiconductor device, which is arranged so as not to fit.

33. The multichip semiconductor device according to claim 32,

The plurality of semiconductor devices are formed on a semiconductor chip,

The inductance element of the semiconductor device is formed on a part of one half of a semiconductor chip, and the inductance element of another semiconductor device adjacent to the semiconductor device is formed on a part of the other half of the chip. A multi-chip type semiconductor device characterized by the above-mentioned.

3 4. The multi-chip semiconductor device according to claim 32, wherein each of the plurality of semiconductor devices is a nonvolatile memory or a microcomputer with a built-in nonvolatile memory.

35. The multichip semiconductor device according to claim 32,

The nonvolatile memory or the microcomputer with a built-in nonvolatile memory is a flash memory or a microcomputer with a built-in flash memory.